Glycolic acid-induced disruption of epidermal homeostasis in a skin equivalent model: Insights into temporal dynamics and mechanisms.

Glycolic acid (GA) is extensively used in cosmetic formulations and skin peeling treatments but its adverse effects, notably severe disruption of epidermal structure, limit its clinical utility. However, the detailed impact of GA on epidermal homeostasis, including changes in structure and protein expression over time, is not fully understood. This study employed a reconstructed human epidermis (RHE) model to assess the effects of varying GA concentrations on epidermal proliferation, differentiation, and desquamation at different time points. Through histology, immunofluorescence, and immunohistochemistry, we observed that 35% GA concentration adversely caused abnormal epidermal homeostasis by affecting epidermal proliferation, differentiation and desquamation. Our findings reveal time-specific responses of key proteins to GA: Filaggrin, Involucrin, Loricrin, and Ki67 showed very early responses; KLK10 an early response; and AQP3 and K10 late responses. This research provides a detailed characterization of GA's effects in an RHE model, mimicking clinical superficial peeling and identifying optimal times for detecting GA-induced changes. Our results offer insights for designing interventions to mitigate GA's adverse effects on skin, enhancing the safety and efficacy of GA peeling treatments.

Facial Skin Aging Characteristics of the Old-Perceived Age in a 20-40 Years Old Chinese Female Population.

Purpose: In the quest for a youthful appearance, women use a variety of anti- aging cosmetics. Defining skin problems is especially important for the selection of anti-aging solutions. However, the skin problems faced by Chinese women at different ages are different. This study aimed at Chinese women aged 20-40 years old and analyzed facial skin aging characteristics of those with old-perceived age. Patients and Methods: The total of 400 standard facial photographs from Chinese female volunteers aged 20-40 was assessed by another 126 Chinese women. The facial areas and skin aging characteristics that influenced age estimation were collected at the same time. Skin aging characteristics, including wrinkles, skin tone, pigmentation and pores, were analyzed based on facial photographs. Groupings were made based on deviation of perceived age from chronological age, and skin aging characteristics among groups were compared. Results: The perceived age of Chinese women aged 20-40 has a moderate correlation with chronological age. Women aged 20-30 generally had an old-perceived age. Deep skin tone was a prominent problem in this age group, with those who had the older-perceived age observed the darker and redder skin tone. Women aged 31-40 were perceived partly old but appeared with wrinkle aggravation, as well as deepening of redness, enlarged pores, and increased pigmentation at the mid-face. The perceived older women also had more visible frown lines and darker skin tone at the upper face. Conclusion: The perceived age of Chinese women aged 20-40 tends to deviate from their chronological age. Women aged 20-30 with old-perceived age are associated with deep skin tone, even found darker and redder in older-perceived women group, while women aged 31-40 are associated with wrinkles and deterioration at mid-face area and upper-face problems drive more attention in older-perceived women group.

Pigmented purpura dermatosis-like mycosis fungoides: four case reports and a review of published cases.

Mycosis fungoides (MF) is the most prevalent type of cutaneous T-cell lymphoma and is generally characterized by multiple patches or plaques with fine scales. One of its variants manifests with multiple purpuric eruptions, mimicking benign pigmented purpuric dermatosis (PPD). To investigate clinicopathological features of PPD-like MF patients. We report four PPD-like MF cases and summarize the clinicopathological features described in reports of nine PPD-like MF cases published in the past 20 years. Compared with benign PPD, petechial lesions in PPD-like MF are more generalized, persistent, and resistant to conventional steroid treatment. Histologically, a superficial dermal band-like infiltrate of atypical lymphocytes with epidermotropism seems to be the most common feature of PPD-like MF. A lymphoid phenotype of CD4+ CD7- T cells and a monoclonal T-cell profile, demonstrated by T-cell receptor gene arrangement analysis, favour a diagnosis of PPD-like MF. Although the exact relationship between PPD and PPD-like MF remains unclear, our study has attached importance to the differential diagnosis of the two diseases in cases of overlooked MF variants. If persistent or generalized purpuric lesions are present, PPD-like MF should be taken into consideration. A thorough physical examination combined with pathological findings may lead to a correct diagnosis.

Single-cell transcriptomics links malignant T cells to the tumor immune landscape in cutaneous T cell lymphoma.

Cutaneous T cell lymphoma (CTCL) represents a heterogeneous group of non-Hodgkin lymphoma distinguished by the presence of clonal malignant T cells. The heterogeneity of malignant T cells and the complex tumor microenvironment remain poorly characterized. With single-cell RNA analysis and bulk whole-exome sequencing on 19 skin lesions from 15 CTCL patients, we decipher the intra-tumor and inter-lesion diversity of CTCL patients and propose a multi-step tumor evolution model. We further establish a subtyping scheme based on the molecular features of malignant T cells and their pro-tumorigenic microenvironments: the TCyEM group, demonstrating a cytotoxic effector memory T cell phenotype, shows more M2 macrophages infiltration, while the TCM group, featured by a central memory T cell phenotype and adverse patient outcome, is infiltrated by highly exhausted CD8+ reactive T cells, B cells and Tregs with suppressive activities. Our results establish a solid basis for understanding the nature of CTCL and pave the way for future precision medicine for CTCL patients.